Effect of titanium adhesion layer on the thermal stability of platinum films during vacuum high temperature treatment

To investigate the thermal effect of the titanium (Ti) adhesion layer on the evolution of structure and properties of platinum (Pt) films, Pt films with different thicknesses of Ti adhesion layers were prepared using magnetron sputtering followed by vacuum heating. Results show that Ti particles diffused into the Pt film, and the level of Ti content on the surface is positively correlated with the proportion of Ti layer thickness. After high temperature annealing, particle agglomeration and recrystallisation of pure Pt films are intensified. Introduction of Ti adhesion layer can inhibit dewetting. With the increase of heat temperature, the enhanced atomic mobility leads to the intensification of Ti diffusion, and the alloying with Pt occurs more fully. The dominant phase in the film gradually changes from Pt to Pt8Ti and then Pt3Ti phase. Although the formation of intermetallic compounds leads to a gradual increase of the electrical resistivity, the introduction of Ti layer can greatly improve the adhesion force of the film and the substrate. In addition, due to that the Pt layer on the Ti layer can relieve some of the tensile stresses through deformation, the addition of the Ti layer can decrease the residual stress of the film.